May 7, 2014:

To enable rapid progress, I may need some volunteers to make a few printed parts for the 6DOF actuators that control the position of the extruder head.  Basically, it's a planetary gear system driven by a NEMA 8 stepper that "worm gears" a 5x1 mm threaded rod - thus creating a linear actuator.   Note:  dimensions are liable to change on my whim ... usually driven by "aw sh...ts" during attempted assembly.  Will know more by next week.